Super-sized ship to install giant wind turbines

Pete Danko EARTHTECHLING, 22nd October 2016

Here's at least least one consequence of super-sizing offshore wind turbines that you might not have considered: The equipment needed to install those turbines is getting bigger as well.

A prime example of this phenomenon recently emerged from the Samsung Heavy Industries shipyards at Geoje, at the southern end of South Korea, in the form of the world's largest wind farm installation vessel.

The Pacific Orca is 528 feet long, 160 feet wide and 34 feet deep. On a single foray out to sea, it can transport and install a dozen 3.6-megawatt turbines. Each shipload of those turbines, once in the place, spinning away for a year, generates enough power to meet the needs of around 12,000 average U.S. homes.

But this ship can handle even bigger turbines, even beyond the 5 and 6 MW turbines with their turbine blades measuring 75 meters in length; it's ready to take on the 10 MW turbines that the industry is envisioning out toward 2020.

Until then, there are a lot of turbines to go in, as offshore wind capacity grows rapidly from the current level under 5 gigawatts to perhaps five times that by 2017, according to International Energy Agency estimates [PDF]. Even at 5 MW apiece, it would take 4,000 new turbines to make that leap, so clearly there is plenty of business for the Pacific Orca.

How does the thing work? A key is those six tall stanchions you see rising from the vessel. Those are known as jackup legs. Those six legs descend to the seabed, as much as 200 feet below – deeper than any such vessel, Samsung said – and then float the Pacific Orca 55 meters above sea level.

The company says the vessel can remain stable and at work in winds above 40 mph and waves 8 feet high, using the 1,200-tonne crane embedded on the vessel.

"The fact that we have now successfully built this world's largest wind farm installation vessel guarantees our competitiveness in future bids," Samsung Heavy Industries CEO Roh In-Sik said in a statement. "We also expect that this achievement will create synergies between the shipbuilding business of Samsung Heavy Industries and the wind power business, which is one of the promising renewable energy businesses."

"A remarkable industry trend to note is the largest shipbuilders such as Hundai Heavy Industry, Samsung Heavy Industry, Daewoo Shipbuilding and Marine Engineering and STX shipbuilding are now fully concentrated on the offshore wind orientated business industry," Dr. Rim-taig Lee, Chairman of Korea Wind Energy Industry Association (KWEIA) told the Korean IT Times recently.

Earlier this year, Samsung Heavy Industries announced plans to base its first European wind project — the development of a 7-megawatt (MW) offshore wind turbine — in Methil, a coastal town in Fife, just across the Firth of Forth from Edinburgh.

The Pacific Orca was delivered to Sinagpore-based shipper Swire Pacific Offshore, which said it will be deployed to provide service for the Danish utility company DONG Engery. It's the company's first wind-farm installation vessels, but it has another on order for deliver by the end of the year.